The function of IFNAR2 (interferon alpha and beta receptor subunit 2, Ensembl gene identifier ENSG00000159110) is as follows. Together with IFNAR1, forms the heterodimeric receptor for type I interferons (including interferons alpha, beta, epsilon, omega and kappa) (PubMed:10049744, PubMed:10556041, PubMed:21854986, PubMed:26424569, PubMed:28165510, PubMed:32972995, PubMed:7665574, PubMed:7759950, PubMed:8181059, PubMed:8798579, PubMed:8969169). Type I interferon binding activates the JAK-STAT signaling cascade, resulting in transcriptional activation or repression of interferon-regulated genes that encode the effectors of the interferon response (PubMed:10049744, PubMed:17517919, PubMed:21854986, PubMed:26424569, PubMed:28165510, PubMed:32972995, PubMed:7665574, PubMed:7759950, PubMed:8181059, PubMed:8798579, PubMed:8969169). Mechanistically, type I interferon-binding brings the IFNAR1 and IFNAR2 subunits into close proximity with one another, driving their associated Janus kinases (JAKs) (TYK2 bound to IFNAR1 and JAK1 bound to IFNAR2) to cross- phosphorylate one another (PubMed:10556041, PubMed:11682488, PubMed:12105218, PubMed:21854986, PubMed:32972995). The activated kinases phosphorylate specific tyrosine residues on the intracellular domains of IFNAR1 and IFNAR2, forming docking sites for the STAT transcription factors (STAT1, STAT2 and STAT) (PubMed:11682488, PubMed:12105218, PubMed:21854986, PubMed:32972995). STAT proteins are then phosphorylated by the JAKs, promoting their translocation into the nucleus to regulate expression of interferon-regulated genes (PubMed:12105218, PubMed:28165510, PubMed:9121453). {ECO:0000269|PubMed:10049744, ECO:0000269|PubMed:10556041, ECO:0000269|PubMed:11682488, ECO:0000269|PubMed:12105218, ECO:0000269|PubMed:17517919, ECO:0000269|PubMed:21854986, ECO:0000269|PubMed:26424569, ECO:0000269|PubMed:28165510, ECO:0000269|PubMed:32972995, ECO:0000269|PubMed:7665574, ECO:0000269|PubMed:7759950, ECO:0000269|PubMed:8181059, ECO:0000269|PubMed:8798579, ECO:0000269|PubMed:8969169, ECO:0000269|PubMed:9121453}. [Isoform 3]: Potent inhibitor of type I IFN receptor activity. .